​Like all pioneer settlements, Margaritaville is not just a place but an idea — an imagined utopia, in this case inspired by a Jimmy Buffett song’s reference to a frozen cocktail.

To be sure, Margaritaville is not representative of how most of us will spend our retirement years. Fewer than 14 percent of Americans 75 and older occupy some form of senior housing today. Three-quarters of those over 50 say they would prefer not to move at all.

And untold numbers of seniors who might need or want to enter an age-restricted or assisted-living community won’t be able to afford to do so; 30 percent of those 65 and older have an annual income below $23,000, according to a study by the Kaiser Family Foundation.

The least-expensive homes in Margaritaville are more than 10 times that, before the monthly association fee of roughly $200 — and those sums don’t include meals or care. (For statewide comparison, a private room in a skilled-nursing facility has a median cost of $9,000 per month, and in an assisted-living residence, $3,500 per month, according to LeadingAge Florida, an association of elder-care organizations.

​Continuing-care communities that guarantee all levels of lifetime care on-site have charges that range from $2,500 to $5,400 per month, plus substantial entry fees.)